"No one else does what they do" in the Persian Gulf, said Gen. Joseph Votel, commander of U.S. Central Command. "So this in my view is not about the Iranian people it's about the Iranian regime and their desire to continue to do these type of things that stoke instability, or attempt to stoke instability in the region", he said.
"I think the big concern here is miscalculation, that I'm very confident in the measures that our maritime forces are taking".
Votel praised the USA sailors' handling of the incidents.
Votel explained that the risky encounters are the result of certain Iranian leaders seeking to "exert their influence and authority in the region".
Last December, Iranian ships fired rockets near a US warship and other vessels in the Strait of Hormuz, and a month later flew an unarmed drone over the USS Harry S. Truman aircraft carrier in the Persian Gulf. "We're talking seconds here", he said about trying to avoid a confrontation between the two militaries.
Last Wednesday, the USS Squall, a coastal patrol ship, fired three warning shots on an Iranian boat that was approaching, head-on, another coastal patrol ship - the USS Tempest.
Iran's Defense Minister Hossein Dehqan has said his nation has the right to investigate or confront foreign vessels near its shoreline.
An Iranian Revolutionary Guard Corps Navy (IRGCN) missile ship and three fast attack craft "demonstrated aggressive behavior in the vicinity of our ship", he said.
"They don't come from the general Iranian navy; only a very, very small percentage of them do", he said.
Last year, Secretary of State John Kerry suggested the nuclear deal might improve ties.
Further, since July, there have been 11 risky confrontations, according to the data, in a sign of increasing Iranian aggression in the Persian Gulf and Strait of Hormuz. "No one else does what they do in the Arabian Gulf", Votel said. I call on Iran to be the professional force that they claim to be.
The Navy estimates about 10 percent of all its interactions with Iranian military vessels since the beginning of 2015 have been unprofessional.
He described the move as "unsafe and unprofessional" encounter between Tehran and Washington, adding that the Iranian vessels came within 300 yards (meters) of the American destroyer.